For highly concentrated refining, CTMP, TMP, fluffing and highly concentrated grinding of sack paper and other lignocellulose-containing material, refining apparatus or disc refiners are used. Examples of refining apparatus are described in U.S. Pat. No. 6,957,758 and EP Patent No. 386, 031. Refining apparatus usually comprise two opposite refining discs rotatable in relation to each other, where usually one refining disc is rotatable, a so called rotor, and one refining disc is non-rotatable, a so called stator, but in some refining apparatus both refining discs are rotatably arranged. The refining discs in this type of refining apparatus are provided with replaceable refining segments which form the refining surfaces of the refining apparatus. The refining segments comprise bars and intermediate grooves. Refining occurs between the two refining surfaces which are held at a certain distance from each other, whereby a space, known as a refining gap, is provided between the refining surfaces.
If the refining surfaces were to come in contact with each other during operation, this will result in a risk of a breakdown or at least result in wear of the refining surfaces, and thus a shortened operating performance. Furthermore, the degree of alignment between the refining surfaces has a crucial importance for the quality of the ground material. When the degree of alignment between the refining surfaces decreases, the quality of the refined material is deteriorated. A correct alignment between the refining surfaces is therefore of great importance.
To obtain a correct alignment between the refining surfaces of the refining discs it is a prerequisite that the rotation axle, to which the rotor is attached, obtains correct alignment. To angle the axle in relation to the horizontal plane and the vertical plane, two alignment devices are used, which align the whole axle package, to which the axle and the rotor belongs. Such an alignment device according to known technology is described in more detail in the detailed description in connection with FIGS. 1 to 6. The alignment of the axle package, and thus of the axle and the rotor, is performed with approximately one-month intervals for a refining apparatus in operation. The adjustment of the axle along its own longitudinal axis is performed by means of another adjustment device which displaces the whole axle package in relation to the support in the direction of the longitudinal axis of the axle. This lengthwise adjustment of the axle package, and thus of the size of the refining gap, is performed several times per second, as the refining gap often must be reduced or increased because of the constant change in the quality of the material intended for refining, such as the amount of material per time unit. To obtain correct alignment between the refining surfaces of the refining discs, an alignment of the refining surfaces themselves in relation to the refining discs also takes place. An example of alignment of the refining surfaces themselves is given in British Patent No. 1,468,649.
Certain problems exist, however, with the present alignment devices for aligning the refining disc of a refining apparatus, of which an example is described in detail in FIGS. 4 to 6.
The requirement that the contact surface of the upper wedge-shaped member against the bearing housing must form different angles with the horizontal plane so that, at different settings of the axle package, they fully bear against the exterior surface of the bearing housing, results in the requirement that the upper wedge-shaped member must rotate in relation to the horizontal plane. This “tilting” of the upper wedge-shaped member results in a relatively large sideway play between the upper wedge-shaped member and the space in the support in which the upper wedge-shaped member is provided. This play results, however, in the upper wedge-shaped member easily jamming in its installation space in the support. Furthermore, the flat contact surface of the upper wedge-shaped member against the bearing housing and the flat contact surface of the bearing housing against the upper wedge-shaped member have a very even surface as these repeatedly slide in relation to each other, which poses high requirements on the machining of these flat surfaces.
The requirement that the actuator of the alignment device must be placed on the side of the support which is facing away from the refining housing, so that the operator is able to control same, has led to a complicated construction of the alignment device, where the alignment by means of the alignment device includes many steps. This also results in a long distance between the securing point of the alignment device in the support and the lower wedge-shaped member, which leads to rendering the respective alignment device sensitive to temperature influence, and in addition the construction is not unresilient enough.
The above-mentioned problems will appear more clearly from the detailed description, where the prior art is described in more detail.
One of the objects of the present invention is thus to provide an alignment of the refining disc of a refining apparatus, which is reliable in service and straightforward to perform.